1. Field of the Invention
The present invention relates to a semiconductor device and a method for manufacturing the semiconductor device. More specifically, the present invention relates to a semiconductor device constituted by electrically connecting electronic components and passive components through bonding wires. The invention also pertains to a method for manufacturing the semiconductor device.
2. Description of the Related Art
In a semiconductor chip (semiconductor element) such as an LSI (Large Scale Integration), for example, capacitors are connected between a power supply circuit and a ground circuit in order to suppress a power supply bounce or GND (ground) bounce caused by simultaneous switching of circuits within the semiconductor chip. As a result, stable feeding can be performed. Such capacitors are referred to as a bypass capacitor.
Further, in order to cut high frequency noises entering through a power supply line, inductors are also connected in series with the power supply line. Such inductors are referred to as a power supply filter.
When thus housing passive elements such as bypass capacitors or power supply filters in a semiconductor device having mounted thereon semiconductor chips and connecting the elements to semiconductor chips, the following advantages can be obtained. That is, the bypass capacitors or the power supply filters can be disposed closer to the circuits within the semiconductor chips, so that operations of the semiconductor chips can be stabled and as a result, electrical characteristics can be improved. Further, passive elements such as bypass capacitors or power supply filters need not be separately mounted on a system board for mounting thereon a semiconductor device, so that the number of components on the system board can be reduced and as a result, miniaturization of this system can be attained.
In such a semiconductor device, there is known a configuration such that using, as a passive element to be built into the device, a passive component in the form of chip component, connection between the semiconductor chip and the passive component is performed by bonding wires.
By using the passive components in the form of chip components, there can be used, for example, common chip components such as chip capacitors or chip inductors of which the outside dimension is standardized, which are referred to as so-called 1005 components, 0603 components or 0402 components. Therefore, semiconductor devices can be manufactured at low cost. The 1005 components have an outside dimension of 1.0 mm×0.5 mm×0.5 mm, the 0603 components have an outside dimension of 0.6 mm×0.3 mm×0.3 mm, and the 0402 components have an outside dimension of 0.4 mm×0.2 mm×0.2 mm. Any component has a shape that electrode terminals are provided on each end in the longitudinal direction.
Herein, there is known a method for interconnecting a passive component and a semiconductor chip using bonding wires (see, e.g., Japanese Unexamined Patent Application Publication No. Hei 8-162607 (FIG. 2), Japanese Unexamined Patent Application Publication No. 2004-47811 (p 18, FIGS. 6 and 7)).
When using this method, an area of a conductive pattern part can be reduced and therefore, a semiconductor device can be miniaturized. Further, a semiconductor chip and a passive component are interconnected using bonding wires without through conductive patterns and therefore, operations of the semiconductor device can be more stabilized, so that electrical characteristics can be improved.
Such passive components in the form of chip components are generally mounted on an inner lead part of a lead frame or a conductive pattern part such as an electrode pad of a wiring substrate using solder or a conductive adhesive in many cases. In this case, a conductive pattern having an area in view of region where solder or a conductive adhesive is wetted and spread is required. Further, a bonding region for connecting between the conductive pattern and the semiconductor chip by bonding wires is required.
Herein, Japanese Unexamined Patent Application Publication No. Hei 8-162607 (FIG. 2) discloses the following configuration. That is, on a die pad of a lead frame, a semiconductor chip and a capacitor are mounted and fixed closely to each other. Further, interconnection among the semiconductor chip, the capacitor and the lead frame is performed by wires. Then, the whole device is sealed with mold resins. In this publication, a method for fixing the semiconductor chip and the capacitor is not described in detail.
On the other hand, Japanese Unexamined Patent Application Publication No. 2004-47811 (p 18, FIGS. 6 and 7) discloses the following configuration. That is, on a die pad (stage) of a lead frame, a semiconductor chip and a passive component are mounted side by side. Further, the semiconductor chip and the passive component are connected through bonding wires. On a portion for mounting the passive component in the die pad, a concave part is formed by etching to allow the whole passive component to be mounted within this concave part through an insulating tape.
By taking such a configuration, the passive component is mounted through the insulating tape. Therefore, electrode terminals provided on each end of the passive component are prevented from coming in contact with the die pad. Further, the passive component is disposed closer to circuits within the semiconductor chip. As a result, electrical characteristics of the semiconductor device can be improved as well as operations thereof can be stabilized. Further, on the die pad, the concave part is formed and the passive component is mounted to fit within the concave part, and therefore, the mounted height of the passive component can be reduced.
However, in these preceding examples, when mounting and fixing the passive component on the die pad, an insulating tape is used as an adhesive material. At this time, a step of preparing a tape processed to a predetermined size and adhering the tape to the concave part is required and therefore, a process is complicated.
A method of using an insulating paste adhesive in place of the insulating tape is also considered; however, this method has a high possibility of causing the following problems in producing semiconductor devices.
(1) In mounting a passive component on an insulating paste adhesive which is coated and supplied on a die pad using a dispenser, when a load imposed on such a passive component excessively increases, electrode terminals of the passive component and the die pad may be brought into contact with each other to cause a short circuit.
(2) On the contrary, when a load imposed on the passive component excessively decreases, the passive component may be obliquely mounted on the die pad. When performing wire bonding to electrode terminals of the passive component in this state, a wire edge may fail to be surely connected to the electrode terminal.